Fuenace for burning coal-dust



B. DEPPEN & E. LEVENGOOD FURNACE FOR BURNING GOAL DUST.

Patented Nov, 16, 1858.

UNITED STATES PAiTENT OFFICE.

G. B. DEPPEN AND E. LEVENG-OOD', OF MYERSTOIVN, PENNSYLVANIA.

FURNACE FOR BURNING COAL-DUST.

Specification of Letters Patent No. 22,067, dated November 16, 1858.

To all whom it may concern:-

Be it known that we, G. B. DEPPEN and E. LEVENGOOD, of Myerstown, in the county of Lebanon and State of Pennsylvania, have invented certain new and'useful Improvements in Furnaces for Burning Coal-Dust; and we do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the accompanying drawings, making a part of this specification, in which Figure 1 represents a side elevation of the furnace. Fig, 2 represents a longitudinal vertical section. Fig. 3 represents a vertical transverse section through the fire chamber, ash pit, &c., and blast regulator. Fig. t represents the perforated plates or bars which we use for holding the fine coal dust.

Similar letters of reference where they occur in the several figures denote like parts of the furnace in all of them.

As the character of the fuel which we propose to use, and for which our furnace is specially constructed, is such as to preclude the use of a natural draft to promote combustion, we connect wit-h the furnace a fan blower for filling the air chamber or chambers, and control the amount of blast by suitable air passages and valves, which make the communication between the blower and the air chamber; and, as ordinary grate bars would not hold up the fuel, on account of the fineness of its particles, which however require fully as much if not more atmospheric air than lump or broken coal, we

are compelled to provide for these requirements. and while we are aware that an artificial blast has been used in connection with furnaces and that attempts have been made to burn fine fuel yet we do not know that they have been successful in burning coal dust or by the arrangement of furnace and draft which we use. The nature of our invention may be said, therefore, to consist in the manner in which we have arranged and combined the several parts of the furnace so as to adapt it to the successful and economical burning of coal dust, as hereinafter set forth.

To enable others skilled in the art to make and use our invention we will proceed to describe the same with reference to the drawings.

A represents the brick work, shell or case for inclosing the boilers, fire and ash box,

fines, and combustion chamber, as will be described.

B, is the fire chamber, its bottom being composed of perforated plates or bars C, which for the sake of strength to resist warping may have ribs o cast on their underside.

D, is the ash box underneath the fire. Access is had to the ash box or pit by suitable doors, but the ash box is intended to be perfectly tight, or as nearly so as possible, inasmuch as it is also used as an air chamber or receiver from whence the atmospheric air, necessary to promote the combustion of the coal dust, is forced up through the small openings in the plates 0, and through the fuel. This ash pit D, is also divided into as many chambers, as there are boilers by partitions E, so that the draft and heat under each one of the boilers may be regulated independent of that under the others.

In rear of the fire chamber B, there is a fire bridge F over which the flame, heat and gases rise, and thence drive or disseminate themselves in or through a combustion chamber G, in rear of said fire chamber. In rear of this combustion chamber G, there is another chamber H, the two being separated by a partition I, in which there is formed a passage 7), covered by a slide or damper J, for regulating the passage of the gases which after they enter the chamber H, rise and pass out of the stack K.

The draft is a forced one, as above stated, and is efiected as follows: L, is a fan blower, which drives a blast through the trunk M, and thence into an air passage N, passing across underneath the bottom of the ash pit. In each subdivision of the ash pit there is a valve 0, whose handle (l extends to the outside of the shell or case, said valve covering an opening in the air passage N, by which means a regulated volume of air is admitted from the blower into each of the subdivisions, and thence it passes up through the perforations in the plates C, to and through the fuel. There is no other draft contemplated than this forced draft, though when the blower is worked by the engine and steam must be got up before the engine can be worked, the front doors of the ash pit are opened to aid in starting the fires.

When it is considered that there are many hundreds of thousands of tons of coal dust lying useless, besides being a great incumbrance, it will be conceeded how valuable an invention must be that will make this coal dust an economical fuel. We have thoroughly tested the experiment, and We are now successfully burning coal dust as a fuel under the arrangement of furnace herein described.

The advantage of the air trunk, and its regulating valves, as a chamber for holding the compressed air, instead of making the ash box such a chamber, enables us to regulate the draft under any boiler of a series, and thus equalize such draft throughout the series, "While the use of the ash box for the air chamber solely would make the draft strongest nearer the fan or blower and weaker and weaker as it passed to the re mote boilers. Besides we make the valves of the air trunk the regulator of the draft, while in the use of the ash box as an air chamber the blower or fan must be Varied or adjusted to effect a change in the volume of air, and even then the most remote boilers from the fan Would scarcely receive any of the current of air.

Having thus fully described the nature and object of our invention what We claim therein. as new and desire to secure by Letters Patent is In combination with a fan blower to promote combustion, the arrangement of the fire chamber, ash box, perforated plates, combustion and exit chambers, communicating with each other, and with the air trunk leading from the fan blower, substantially in the manner and for the purpose, herein described,

G. B. DEPPEN. E. LEVENGOOD. Witnesses Josnrn COOPER, THOMAS Bassmm. 

